FlyTrapCare Forums

I find myself these days hanging around the house a lot and as Chef says, “idle hands are the playground of the demented”…or something like that. So, I did a little experiment today in my NASA/CDC/SETI/FDA/GSA certified laboratory.

I tested three different waters at three different temperatures with my hi-tech Dumbmaker TDS meter...range of 0 to 9990ppm, accuracy of +/-2%. The three types of water consisted of fresh rain water, some stored water, and tap water from my hi-tech kitchen sink. I took samples and recorded the temperature and TDS reading. I then heated those samples up slightly in the microwave and re-tested them. I then heated the sample one more time and tested again. The strong smell of popcorn coming from the Mars lander-grade microwave did not affect the results of these highly precise tests. Here are the results from my pristine, highly-sanitized and homogenized laboratory.

Tap water (from my hi-tech kitchen sink)
Temp 58F TDS 300ppm
Temp 82F TDS 396ppm
Temp 90F TDS 424ppm

Stored rain water
Temp 52F TDS 9ppm
Temp 82F TDS 14ppm
Temp 90F TDS 16ppm

Fresh rain water
Temp 48F TDS 2ppm
Temp 80F TDS 3ppm
Temp 91F TDS 4ppm

For *my* situation, it doesn't make a hill of beans what the temperature is when measuring presumed low-ppm types of water, specifically rain water. Even a presumed higher-ppm such as RO water shouldn't have a big swing in measurement due to temperature.

But, when you get to high-ppm tap/faucet water the increase in temperature does make a significant difference...but, I'm not going to be using it for watering my CPs anyhow so it doesn't make mean a hill of beans to me, either.

All this science doo-dad stuff is making my head hurt. I need to take a break. The sacrifices us scientist make....

TDS meters measure conductivity. The more minerals, the higher the conductivity, the higher the reading. Temperature affects the reading because heat excites the molecules, making them move faster, increasing the conductivity, resulting in a higher reading. The truest measurement is generally taken at 70-75°F (~22-25°C). The TDS meters most of us have simply read it as is, but some of the more fancy-pants ones will correct to ~70°F.

Let me pose a question. If I have 5 one-gallon jugs of 8ppm rain water is it worth the trouble of pouring it out and refilling with some 2ppm water that I’ve collected? Is the difference of 6ppm a notable difference?

You don't have enough plants.
Water your plants with the 5 gallons of 8ppm water.
Then refill your jugs with the 2ppm fresh water.
The difference is negligible.
Just my 02¢ worth.

^^^^What he said. Plus, like last summer, you'll likely run out of rain water. This is five gallons of delaying that.

Mike, I agree...I don't have enough plants but I'm working on it...just gotta work some kinks out (most of them in between my ears!<g>)

Ok, ok,...I'll try to figure out somewhere to put it and use the 8ppm, too. I wonder if the town is using the old water tank.<grin> Right now I have around 20-gallons in milk jugs (mostly 1-3ppm, except for the recent 8ppm jugs)...this is my "working supply". Then there's the 32-gallons (8ppm) in a plastic garbage can...the "strategic reserve". Lastly, another ~11-12 gallons (2-3ppm)in two plastic buckets...my "strategic strategic reserve". There's closer to probably eight gallons of the 2ppm water sitting out there now...I've got three jugs I available now and I guess I can just cap off the big bucket for a while until I free up some more jugs. I think I'll do that. A few of my buckets are getting old and brittle which makes you nervous when moving them filled with water, but have you checked the price of new buckets at Lowes or HD???!!!! The Lowes blue buckets and HD orange buckets are $5 and the foodgrades are $8.00 and $8.50, respectively!!! For handling water the buckets are great and for smaller bulk storage containers, but for major storage I'll be looking for the 32-gallon size or larger containers. A year ago I really had no inclination to store rain water...then my granddaughter bought a flytrap at Walmart. It's all her fault!!!

Edit: I had to add “on it” to my reply to Mike…left it out for some reason! It sounded like I was working so much I couldn’t handle any more plants. My wife will be the first to attest that I ain’t been working (much less, too much!!)

ChefDean wrote: ↑Tue Jan 24, 2023 12:56 am TDS meters measure conductivity. The more minerals, the higher the conductivity, the higher the reading. Temperature affects the reading because heat excites the molecules, making them move faster, increasing the conductivity, resulting in a higher reading. The truest measurement is generally taken at 70-75°F (~22-25°C). The TDS meters most of us have simply read it as is, but some of the more fancy-pants ones will correct to ~70°F.

Yes, and conversely, the higher the resistance (typically Mohms) the more pure the water. The inline sensors on DI water systems are set to pop an alarm if the resistance falls below 18 Mohms. Pharmaceutical companies use a LOT of 18 Mohm deionized water in cleaning process equipment.